Finished the main game + Descent + Trespasser in early 2020, but recently I've been coming back to the game to finish open world stuff I had left, so I decided to also start the DLC and it was a great choice! Hakkon brings a totally new region, with its own lore, main story and conflict. In a lot of ways, it's like any other region of the main game but better. It uses many of the open world systems and type of quests you can find in other zones but they feel more natural and necessary, and the narrative keeps things varied and interesting.